1. Field of the Invention
This invention generally relates to a bag manufacturing and packaging apparatus. More specifically, the present invention relates to a bag manufacturing and packaging apparatus that forms a strip film into a tubular shape, manufactures bags filled with articles, and mounts those bags to a strip narrower than the bags.
2. Background Information
In one mode of displaying articles in a retail store, a plurality of bags in which articles like snacks and candies are filled and packaged, are attached to a strip for displaying the articles, leaving a small gap between each bag. This way, the bags are arranged vertically by hanging the end of the strip. A suspended bag can be removed from the strip by a customer without damaging the seal of the bag by pulling the bag downward and thereby detaching the bag. To manufacture such an apparatus, it has been suggested to impart to a bag manufacturing and packaging apparatus a function that mounts manufactured bags to a strip. Examples of such bag manufacturing and packaging apparatus are shown in Japanese translation of PCT Application Publication 9-508879, U.S. Pat. No. 3,864,895, and PCT International Application Publication 98/52823.
Further, as recited in Japanese Patent Application No. 2002-251845, the assignee company of the present applicant has proposed a bag manufacturing and packaging apparatus including: a bag manufacturing unit 10 that forms a strip film F into a tubular form and manufactures a bag B filled with articles C; a feed roller unit (drive roller 41c) that feeds a strip S, which is narrower than the bags B and to which bags B manufactured by the bag manufacturing unit 10 are mounted; and a strip mounting unit 30 that mounts the bags B to the strip S fed by the feed roller unit.
Incidentally, as depicted in FIG. 8 of Japanese Patent Application No. 2002-251845, the feed roller unit is arranged spaced apart by a certain amount from the strip mounting unit 30 in order to avoid interfering with the strip mounting unit 30 or a transfer mechanism 32, which transports bags B from the bag manufacturing unit 10 to the strip mounting unit 30. If the strip S is formed from a stiff material, such as coated paper, or formed with a thickness greater than or equal to a prescribed thickness, then the strip S fed from the feed roller unit is fed smoothly as far as the strip mounting unit 30, without sagging downward.
Nevertheless, if the strip S is formed from a material such as a thin resin that lacks rigidity, then the strip S will unfavorably sag downward between the feed roller unit and the strip mounting unit 30, and may not feed smoothly. Accordingly, problems such as jamming of the strip S in the guide unit 49 (discussed later) and the like may arise, and unevenness in the mounting gap of the bags B on the strip S may result.
In addition, the above-mentioned bag manufacturing and packaging apparatus is constituted so that a cutter 45 between the feed roller unit and the strip mounting unit 30 operates and forms slits in the strip S so that the strip S, to which bags B are mounted, can be cut in the retail store into lengths appropriate to display the articles. At that time, it is necessary to apply tension to the Strip S and hold it so that the Strip S does not escape from the cutter 45. However, since the strip S is merely held by the feed roller unit, tension cannot be applied to the strip S when forming a slit. Furthermore, in the strip mounting unit 30, because bags B are pressed (thermally welded) to the strip S by a pressing body 33c on a heater 33a, the strip S is held by the feed roller unit and the pressing body 33c, such that tension can be applied to the strip S. However, the pressing time is set extremely short so that the heat does not burn through the strip S. Accordingly, it is difficult to adjust the timing at which the cutter 45 should be operated, because there is limited timing for the operation of the cutter 45. Therefore, the guide unit is provided at the perimeter of the cutter 45, which guides the strip S in the transport direction and also ensures that the strip S does not escape from the cutter 45.
Nevertheless, if the strip S is formed from a thin resin that lacks rigidity, and if slits are formed in a state wherein tension is not applied to the strip S, then slits cannot be formed by just sliding the strip S over the cutter. Furthermore, because the guide unit merely planarly guides the strip S only on its upper and lower surfaces, the strip S may drift in the transverse direction in the guide unit, and may not be fed smoothly. As a result, the strip S may get caught in and jammed by the guide unit. As a result, slits may not be accurately formed in the strip S, and the strip S may develop wrinkles, degrading its appearance.
Furthermore, when initially setting the strip S or if, instead of forming slits as described above, the strip S is completely cut, then it will be necessary to thread the strip S by hand from the feed roller unit up to the strip mounting unit 30, making it unamenable to automation.
In view of the above, there exists a need for a bag manufacturing and packaging apparatus which overcomes the above mentioned problems in the prior art. This invention addresses this need in the prior art as well as other needs, which will become apparent to those skilled in the art from this disclosure.